From e675447bda51c1ea72d1ac9132ce3bed974f1da3 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 4 Jul 2016 09:50:15 +0000 Subject: [PATCH] timers: Make 'pinned' a timer property We want to move the timer migration logic from a 'push' to a 'pull' model. Under the current 'push' model pinned timers are handled via a runtime API variant: mod_timer_pinned(). The 'pull' model requires us to store the pinned attribute of a timer in the timer_list structure itself, as a new TIMER_PINNED bit in timer->flags. This flag must be set at initialization time and the timer APIs recognize the flag. This patch: - Implements the new flag and associated new-style initialization methods - makes mod_timer() recognize new-style pinned timers, - and adds some migration helper facility to allow step by step conversion of old-style to new-style pinned timers. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Cc: Arjan van de Ven Cc: Chris Mason Cc: Eric Dumazet Cc: George Spelvin Cc: Josh Triplett Cc: Len Brown Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rik van Riel Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160704094341.049338558@linutronix.de Signed-off-by: Ingo Molnar --- include/linux/timer.h | 25 ++++++++++++++++++++++--- kernel/time/timer.c | 10 +++++----- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/include/linux/timer.h b/include/linux/timer.h index 20ac746f3eb3..046d6cf26498 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -62,7 +62,8 @@ struct timer_list { #define TIMER_MIGRATING 0x00080000 #define TIMER_BASEMASK (TIMER_CPUMASK | TIMER_MIGRATING) #define TIMER_DEFERRABLE 0x00100000 -#define TIMER_IRQSAFE 0x00200000 +#define TIMER_PINNED 0x00200000 +#define TIMER_IRQSAFE 0x00400000 #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \ .entry = { .next = TIMER_ENTRY_STATIC }, \ @@ -78,9 +79,15 @@ struct timer_list { #define TIMER_INITIALIZER(_function, _expires, _data) \ __TIMER_INITIALIZER((_function), (_expires), (_data), 0) +#define TIMER_PINNED_INITIALIZER(_function, _expires, _data) \ + __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED) + #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) \ __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE) +#define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data) \ + __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED) + #define DEFINE_TIMER(_name, _function, _expires, _data) \ struct timer_list _name = \ TIMER_INITIALIZER(_function, _expires, _data) @@ -124,8 +131,12 @@ static inline void init_timer_on_stack_key(struct timer_list *timer, #define init_timer(timer) \ __init_timer((timer), 0) +#define init_timer_pinned(timer) \ + __init_timer((timer), TIMER_PINNED) #define init_timer_deferrable(timer) \ __init_timer((timer), TIMER_DEFERRABLE) +#define init_timer_pinned_deferrable(timer) \ + __init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED) #define init_timer_on_stack(timer) \ __init_timer_on_stack((timer), 0) @@ -145,12 +156,20 @@ static inline void init_timer_on_stack_key(struct timer_list *timer, #define setup_timer(timer, fn, data) \ __setup_timer((timer), (fn), (data), 0) +#define setup_pinned_timer(timer, fn, data) \ + __setup_timer((timer), (fn), (data), TIMER_PINNED) #define setup_deferrable_timer(timer, fn, data) \ __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE) +#define setup_pinned_deferrable_timer(timer, fn, data) \ + __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED) #define setup_timer_on_stack(timer, fn, data) \ __setup_timer_on_stack((timer), (fn), (data), 0) +#define setup_pinned_timer_on_stack(timer, fn, data) \ + __setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED) #define setup_deferrable_timer_on_stack(timer, fn, data) \ __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE) +#define setup_pinned_deferrable_timer_on_stack(timer, fn, data) \ + __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED) /** * timer_pending - is a timer pending? @@ -175,8 +194,8 @@ extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires); extern void set_timer_slack(struct timer_list *time, int slack_hz); -#define TIMER_NOT_PINNED 0 -#define TIMER_PINNED 1 +#define MOD_TIMER_NOT_PINNED 0 +#define MOD_TIMER_PINNED 1 /* * The jiffies value which is added to now, when there is no timer * in the timer wheel: diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 3a95f9728778..693f6d14058e 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -782,7 +782,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, debug_activate(timer, expires); - new_base = get_target_base(base, pinned); + new_base = get_target_base(base, pinned || timer->flags & TIMER_PINNED); if (base != new_base) { /* @@ -825,7 +825,7 @@ out_unlock: */ int mod_timer_pending(struct timer_list *timer, unsigned long expires) { - return __mod_timer(timer, expires, true, TIMER_NOT_PINNED); + return __mod_timer(timer, expires, true, MOD_TIMER_NOT_PINNED); } EXPORT_SYMBOL(mod_timer_pending); @@ -900,7 +900,7 @@ int mod_timer(struct timer_list *timer, unsigned long expires) if (timer_pending(timer) && timer->expires == expires) return 1; - return __mod_timer(timer, expires, false, TIMER_NOT_PINNED); + return __mod_timer(timer, expires, false, MOD_TIMER_NOT_PINNED); } EXPORT_SYMBOL(mod_timer); @@ -928,7 +928,7 @@ int mod_timer_pinned(struct timer_list *timer, unsigned long expires) if (timer->expires == expires && timer_pending(timer)) return 1; - return __mod_timer(timer, expires, false, TIMER_PINNED); + return __mod_timer(timer, expires, false, MOD_TIMER_PINNED); } EXPORT_SYMBOL(mod_timer_pinned); @@ -1512,7 +1512,7 @@ signed long __sched schedule_timeout(signed long timeout) expire = timeout + jiffies; setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); - __mod_timer(&timer, expire, false, TIMER_NOT_PINNED); + __mod_timer(&timer, expire, false, MOD_TIMER_NOT_PINNED); schedule(); del_singleshot_timer_sync(&timer); -- 2.20.1